Rob, from what I'm hearing from all carriers, you should be pleasantly surprised. The intent of RIM was to have the upgrade available when they launched BES 4.1 SP5 and shortly thereafter BIS 2.5. The initial date for the BES upgrade was November and then moved back to mid-February. It has since been removed from the Life Cycle portal, so it's status is currently in limbo. The latest beta OS versions we have are still OS 4.3.1. If there is a delay, it's fairly last minute and should not hold up release more than a month or so, in my opinion. If the delay ends up being fairly big, I wouldn't doubt it's release in the Asian market followed up by a few more rounds of QA and possibly an April release. It'll be out before May, unlike BES 5.0 (which was initially slated for a May 2008 release, per RIM's announcements last year at WES ...it's currently in pre-beta and has slipped no less than 6 months, possibly 9-12 months).
In the beginning the Universe was created. This has made a lot of people very angry and is widely regarded as a bad move.